UTC Desire C USA/Canada/Europe compatibilitySupport

I just bought a HTC Desire C in Canada. It's quad frequencies on GSM but is missing 2 frequencies on 3G (850, 1900) to keep the cost low. If I succeed to unlock the phone, can I use the same phone in Europe/US? What are the pros/cons of buying this phone in Canada for international use? does it severely limit my 3g use?